Spring jack



1,617,477, Feb. 15,l927. RACLARKE SPRING JACK Filed Jan. 14, 1924 posedfor easy connection into a circuit, has no insulating member subject toWear, has

1,617,477 as i oeei ca RALPH ALBERTO CLARKE, or s1. ALBANS, VERMONT,ASSIGNOR TO FRANKLIN [RADIO 7 COMPANY, or 'sr. ALBANS, VERMONT,Acoitr-oaATioN-oii VERMONT:

SPRING JACK.

Application filed January 14, 1924. Serial 'No. 686,094.

This invention relates to certain new and.

useful improvements in spring jacks which are particularly adaptedfor'usewith radiocommunication circuits and apparatus. Parit isnecessary toreducethe capacitive effects between the conductive portionsof the'apparatus. Such apparatus often have one or more stagesofamplification, and it'is custornary to couplethe reproducinginstrument to the apparatus proper by the use of a springqack foreachstage, to receive a plug member connected to the reproducer; and toprovide contact'members in the jack to control the circuits in theapparatus. Owing to tlie'large areas and short distances used incurrently manufactured jacks, a high capacitive'eii'ect exists, to theserious impairment of'the selectivity of theapparatus.

It is therefore an object of thisinvention to so design'and arrange theelements of the spring-jack as to produce anflarticle' which occupiesslight space,"is cheap in manufacture and easy to mount, has itsterminals disits several elements spaced apart and having relativelysmall capacitive surfaces, is'readily adapted to the Various circuits,and is shielded against body-capacity effects.

In the accompanying drawings are shown several modifications oftheapplication' of circuits. Fig. l'is an open circuit jack.

Fig. 9. is a double circuit jack. F 3 is a jack similar to that of Fig.2 butwith an additional auxiliary blade. F i'gs. 4and 5 are respectivelya cross-section on line i-t of Fig.2, and aside view of the jack withthe panel in section. 7

My improved spring 'jack comprises a metal supporting member 1 with aninsulating base block 2 thereon to receive and main tain electricallyinsulated from each other the various blade and terminal elements. Athreaded aperture 3 through these members serves toreceive the threadedplug sleeve 4, which passes through the customary panel board 5 ofbakelite or the like, tohold-the member 1 in place by clamping ittightly to the panel board. A screw 6 may likewise be used for thispurpose.

Mounted on this insulating block 2 and this jack consti'uctionforusewith various fastened thereto bindin'g'posts and screws 7 and 8 arethe various spring blades 9,10, 11, 12 of the several figures: Bindingpost screws? are insulated from and recessedin aperti'ires 13 ofthemetal plate 1; while screw 8' is in electrical connection with thespring blade 10 which'niakes contact-with the plug sleeve element, andwith the metal plate'l. The blades may be easily manufactured bypunching substantially L shaped blanks from" sheet metal and thenbending them to the proper form. The attachingfoot 14 isformed'byb'ending one leg of the blank outof its plane; andfthe otherleg or major portion of the spring bladehas itsmaj'or axis disposedchordally with regard toxthe circular base, and substantially radialwith re blades intended to come into c ntact with 'the to the majoraxis'fand"extending? into the path offthe plug; and are adapted to bee'ngard 'to the plug sleeve 4. The 'on'tereiids of j gaged and'niox'edlaterally thereby,".thus

moving the blade in'aplane' parallel-to the base. These cam surfaces 15,16 are disposed at different planes with regard to the base,lso oneofthem makes contactwitlrthe ball-'point'and' the otherwith tliesleeveon the plug. In order to assure the plug against accidental withdrawaland toaflford a proper contact, a ridged? or18 respectively is providedto engage thegroove of are plug.

To cooperate with these" spring blades are. provided terminalinembers'19'whic'h' are similarly" cutout and formed by PlIHClTil'igoperations; They are each'provid'ed with a small projection or contactpoint 20 oftun'gsten or the like to'assure regularcontact with the bladeelement. The ends of the terminal elements are bent and fastened' totlie insulating base block 2 by means of binding posts and screws 21which are insulated from the metal plate and recessed in aperturessimilar to 13.

'The wires used to connect the jack in the circuit or circuits areclamped in the binding posts at 7, 8, and 21. It will be noted thatthese posts may be set at any angle to avoid bends in the wires.

Only a very small area of the terminal member and of the spring bladeare'opposite each other, which assures a very low ca acity when the jackopens the circuit upon t e insertion of the plug. The spring blades tendintroduced;

to bend for their whole length in a plane.

parallel 'totlie base, instead of bending only at the line of contactwith the base, which assures a long life and full flexibility.

The various figures show theapplicability of the construction of varioustypes of jacks. In Fig. 1 is a so-cal lcd single circuit jack. The plughas but a single contact member which cooperates with the spring blade9. This blade opens a circuit by moving away from'the contact point- 20when the plug is In Figs. 2, 4t and 5 is a more complex type,

with two'inoving blades to make contact respective'ly with the ball-tipand the sleeve of a standardplug, as shown in Fig. 5.

In this case each blade opens a circuit upon the iiitroductioii of theplug. The system allows a wide separation of the, spring blades and theterminal members.

Fig. 3 shows a still more complex type, in-

dicating the possibilities of assembly on a base ofa single size. Inthis case the two right-hand spring blades function as in Fig. 2. but inaddition to this, an insulating pillar 22 added, between the springblade 11 and I Lthe auxiliary springblade 12. This latter spring bladehas 'no direct electrical or V mechanical connection Withthe otherblades orthe plug except by this pillar; it controls two circuits, onebeing open when the plug 1 is in the jack, and the other being open whenthe plug is Withdrawn. As before a wide. space is presented between theblades and terminal members.

. These modificationsof the a plicatio of 1 the new, principle ofconstruction indicate its adaptability to the various types of jackswhich are required for various circuit comb nations. V

I claim:

1. In a spring jack, a base and a spring blade held substantially atright angles to "said base and having an integral laterally OfiSGtsupporting portion with a bent foot secured to said base, said bladehaving a plug receiving {portion and adapted to be bent by suchplug uponinsertion into the jack in a direction substantially parallelto theplane of said base.

2. In a spring jack, a base, a spring conltact blade held substantiallyat right angles angles to its plane, and a plurality of spring bladeseach held substantially at right angles to said base and having anintegral laterally offset supporting portion with a bent foot secured tosaid base, each of said blades having a plug receiving portion andadapted to be bent by such plug upon insertion into the jack in adirection substantially parallel to the plane of the said base, saidblades being insulated from each other and converging from theirrespective securing points to present their respective plug receivingportions opposite said aperture at different distances from the plane ofsaid base.

4. In a spring jack, an insu'latingbase member having a plug sleeveeccentrically mounted therein, a spring blade mounted on said base andextending chordally across said base and presenting its free endopposite said sleeve and being adapted to move in a plane substantiallyat right angles to the axis of said sleeve.

5. In a'spring jack, an insulating base member having a plug sleevemounted there- 111,3I1Cl a plurality of spring blades mounted forresiliency in a plane sbustai tially parallelto said base and convergingtowards said sleeve.

6. In a spring jack, an insulating base, a plug sleeve mounted in saidbase, a plurality of insulated spring blades mounted by lateral feet onsaid base, and having cam vsurfaces thereon opposite said sleeve, the

cam surfaces on said blades being disposed in different planessubstantially parallel to said base, and said blades beingdisposed forresiliency in said planes.

In testimony whereof, I'aflix my signature.

RALPH ALBERTO CLARKE.

